Neural & Hybrid Computing Laboratory

Department of Biomedical Engineering, University of
Florida

Poly-HEMA
as a Drug Delivery Device for
In Vitro Neural Networks on Micro-Electrode Arrays

(Abstract)Delivery
of pharmacological agents in vitro can often be a
difficult, time consuming, and costly process. In this
paper we describe an economical method for in vitro
delivery using a hydrogel of poly hydroxyethyl methacrylate
(PHEMA) that can absorb up to 50% of its weight of any
water-solubilized pharmacological agent. This agent will
then passively diffuse into surrounding media upon
application in vitro. An in vitro test of PHEMA as a drug
delivery device was conducted using dissociated rat
cortical neurons cultured on microelectrode arrays. These
microelectrode arrays permit the real-time measurement of
neural activity at sixty different sites across a network
of neurons. Neural activity was compared during the
application of PHEMA saturated with cell culture media and
PHEMA saturated with bicuculline, a widely used
pharmacological agent with stereotypical effects on neural
activity patterns. Application of PHEMA saturated with
bicuculline produced a gradual increase in concentration in
vitro. When the minimum effective concentration of
bicuculline was reached, which was found to be 0.59
micromolar using the diffusion properties of the PHEMA, it
produced the rapid almost periodic synchronized bursting
characteristically associated with this agent. In contrast
application of PHEMA saturated in culture media alone had
no effect on neural activity reinforcing its inherent inert
properties. Since PHEMA is non-toxic, can be molded into a
variety of shapes, quickly manufactured in any laboratory,
and is inexpensive to produce, the material represents a
promising alternative to drug delivery systems on the
market today.
Effect on Interburst Interval after application of a
bicuculine (Treatment) and placebo rings to five cultures
of rat cortical neurons on MEAs relative to
baseline:
Publication: